System and method for caching a network connection

ABSTRACT

The invention relates to a system and method for caching a network connection. The system sustains connections between a server and one or more back-end databases. The server may establish multiple connections with one or more back-end databases based on data requests from one or more users. The server may determine one or more back-end databases from which the data requests may be satisfied. After receiving the data, the users, using an end-user device, may request disconnection of a connection between the end-user device and the server. The server, however, sustains the connection with the back-end database from which the data was retrieved. The server may use this connection to satisfy other data requests without re-establishing a connection with that back-end database.

RELATED APPLICATIONS

This application claims priority from U.S. Provisional PatentApplication Ser. No. 60/209,644, filed Jun. 5, 2000, and entitled“Low-Overhead Hierarchical-Caching-Object Storage Toolkit.” Thisapplication is also related to U.S. patent application Ser. No.09/750,298, filed Dec. 29, 2000, now U.S. Pat. No. 6,745,189, andentitled “System and Method for Enabling Multi-Indexing of Objects;”U.S. patent application Ser. No. 09/750,315, filed Dec. 29, 2000, andentitled “System and Method for Searching Extended Regular Expressions;”U.S. patent application Ser. No. 09/750,317, filed Dec. 29, 2000, andentitled “System and Method for Enabling Statistical Matching;” U.S.patent application Ser. No. 09/750,318, filed Dec. 29, 2000, now U.S.Pat. No. 6,611,897, and entitled “System and Method for ManagingHierarchical Objects;” U.S. patent application Ser. No. 09/750,319,filed Dec. 29, 2000, and entitled “System and Method for StoringConceptual Information;” and U.S. patent application Ser. No.09/750,322, filed Dec. 29, 2000, now U.S. Pat. No. 6,323,328, andentitled “System and Method for Enabling Unified Access to MultipleTypes of Data.” Each of the applications identified above is hereinincorporated by reference.

FIELD OF THE INVENTION

The invention relates to a system and method for caching a networkconnection. More particularly, the invention relates to a system andmethod that sustains a connection between a server and a back-enddatabase after a connection between an end-user device and the serverhas been disconnected.

BACKGROUND OF THE INVENTION

Modern database applications are typically designed using relationaldata models that are implemented by well known technologies such as DB2.For many applications, a relational data model works well. For someapplications, however, the relational database model limits the abilityto represent complex conceptual information. Such systems typicallystore data in tables that include one or more columns. When data isstored in the tables, the data may not occupy all or a portion of one ormore columns. Therefore, data storage space that includes unused columnsmay be unused. Additionally, such systems typically require a new tableschema to be defined for each data collection to be saved. Therefore,data to be stored must be assembled by the system to populate thetable's schema within the table. Additionally, systems typically onlyallow navigation through the table in a downward direction.

These tables contain named columns of information and one row for eachdata observation. Related tables may be joined by one or more columnsthat contain a common field. The descriptions of all tables, columns,and relationships are contained in the database schema, which istypically maintained by a full-time database administrator (DBA). Thedefinition of new tables, columns, or relationships usually requires theintervention of a DBA.

Many applications typically store dense lists of information, such asfinancial data or employee records, where most data columns are fullypopulated. Other applications, such as name and address directories orproduct catalogues, contain sparse information. That is, out of manypotential data elements, only a few may exist in any particular record.Address directories and product catalogues typically maintainrelationships, especially inheritances that are usually more easilyunderstood when expressed in hierarchical trees rather than joinedrelational tables.

Another drawback of existing systems is that data collections to bestored must be transformed to a format compatible with a table to beused to store the data This may require modification of existing schemaor reformatting a database to a particular format. This may includereorganization and possible downtime for the database.

Another drawback with existing systems is that multiple disk reads maybe necessary for retrieving rows within a table. For example, if a userdesires to further limit a search, and the user inserts additionalcriteria for searching an object, existing systems typically access aserver each time an additional search criteria is input. This may slowthe performance of the server and increase processing time.

Relational databases are used to store relationships among tables.Relational databases, however, are not very suitable for storinghierarchies. Therefore, hierarchical databases typically are used tostore hierarchies. Data elements are stored as fixed lengths. If a dataelement does not occupy the fixed lengths, the excess data storage spacemay be wasted.

Existing systems are typically slow to resolve queries. For example, aquery may take one hundred (100) milliseconds to be resolved. Anotherdrawback is that applications are typically coded to retrieve one or atmost a few attributes on any one server call. This may lead to multiplecalls being issued to a server against the same data collection.Furthermore, because only portions of a data collection are retrieved,existing systems typically parse the data collection for particularinformation being requested. Parsing may occur for each call issued to aserver. This may also increase processing time.

These and other drawbacks exist.

SUMMARY OF THE INVENTION

One object of the invention is to overcome these and other drawbacks ofthe existing systems.

Another object of the invention is to provide a system and method forcaching a network connection.

Another object of the invention is to provide a system and method forcaching a network connection that sustains a connection between a serverand a back-end database after a connection between an end-user deviceand the server has been disconnected.

Another object of the invention is to provide a system and method forcaching a network connection that maintains a record of open connectionsbetween the server and one or more back-end databases.

Another object of the invention is to provide a system and method forcaching a network connection that references the record of openconnections to determine whether a connection to a particular back-enddatabase exists.

Another object of the invention is to provide a system and method forcaching a network connection that reduces connection time.

The invention relates to a system and method for caching a networkconnection. The system sustains connections between a server and one ormore back-end databases. The server may establish multiple connectionswith one or more back-end databases based on data requests from one ormore users. The server may determine one or more back-end databases fromwhich the data requests may be satisfied. After receiving the data, theusers, using an end-user device, may request disconnection of aconnection between the end-user device and the server. The server,however, sustains the connection with the back-end database from whichthe data was retrieved. The server may use this connection to satisfyother data requests without re-establishing a connection with thatback-end database.

The invention also relates to a system and method for storing andtransmitting data. The data may be stored as a hierarchical data list(HDL), hierarchical data container (HDC), or hierarchical data element(HDE). An HDE may include a structure that comprises a ‘name’, syntax,and value. Additionally, an HDE describes its relationship to siblingobjects and/or a parent HDE. One example of an HDE is a linked attributevalue pair (LAVP). An HDC is a particular type of HDE that comprises aname and pointers to a list of zero or more HDEs. An example of an HDCis a linked attribute value list (LAVL). An HDL may be an HDC and itscollection of zero or more HDEs. An example of and HDL may be an LAVLand zero or more LAVPs.

The invention provides a system and method for representing, storing,transmitting, and retrieving information. The invention uses a hybriddata object containing hierarchical information and references back-enddatabases that may be stored with one or more keys that are dynamicallyderived from an HDE's content when the object is stored. The inventionenables sufficient storage and retrieval of HDLs using indexing withStructured Query Language (SQL)-like complex query capabilities. EachHDL and HDE may be a self-defining entity. That is, each HDL and HDEcontains its own schema. Each HDL may contain information to determinethe attributes of the HDL, HDE, and each data element. The inventionalso enables rapid navigation, transmission, searching, construction,manipulation, and deletion of HDLs and HDEs.

The HDL may include collections of HDEs and possibly, other subordinateHDLs. This recursive data architecture enables complex hierarchies ofdata objects and enables data inheritance. Navigation through an HDL maybe forward, backward, up, or down, through a navigational tree. The HDLmay be broken apart and rearranged in any manner desired.

The invention also enables referencing back-end databases such as LDAP,DB2, and Oracle. These data references may be cached and subsequentlyretrieved without referring to the back-end databases. This enablesfaster retrieval of the data objects from such systems. A time-to-livefor each cache entry may be set individually for each cached HDL. Theinvention also enables invalidation of a cached reference and rereadingof a cached reference regardless of a status of the reference.

Each HDL may be stored as an ordinary “flat file,” and may be copied,moved, backed-up, or deleted using known operating system commands. HDLsmay also be replicated to remote locations. Preferably, replication isperformed in real-time.

Other objects, advantages, and embodiments of the invention are setforth in part in the description that follows and in part will beapparent to one of ordinary skill in the art.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic block diagram of a system for storing andtransmitting HDLs according to one embodiment of the invention.

FIG. 2 is a schematic block diagram of a system for storing andtransmitting HDLs according to one embodiment of the invention.

FIG. 3A is a schematic block diagram of an HDL according to oneembodiment of the invention.

FIG. 3B is a schematic block diagram of an HDL stored according to oneembodiment of the invention.

FIG. 4 is a schematic block diagram of a string object stored accordingto one embodiment of the invention.

FIG. 5 is an illustration of an HDL according to one embodiment of theinvention.

FIG. 6A is a schematic block diagram of a client-side system formanaging HDLs according to one embodiment of the invention.

FIG. 6B is a schematic block diagram of a method for managing HDLsaccording to one embodiment of the invention.

FIG. 7 is a schematic block diagram of a server-side system for managingHDLs according to one embodiment of the invention.

FIG. 8 is a schematic block diagram of a system for statistical matchingaccording to one embodiment of the invention.

FIG. 9 is a schematic block diagram of a system for caching a networkconnection according to one embodiment of the invention.

FIG. 10 is a schematic block diagram of a method for caching a networkconnection according to one embodiment of the invention.

FIG. 11 is a schematic block diagram of a method for searching extendedregular expressions according to one embodiment of the invention.

FIG. 12 is a schematic block diagram of a system for searching extendedregular expressions according to one embodiment of the invention.

FIG. 13 is a schematic block diagram of a method for multi-indexing ofobjects according to one embodiment of the invention.

FIG. 14 is a schematic block diagram of a system for multi-indexing ofobjects according to one embodiment of the invention.

FIG. 15 is a schematic block diagram of a method for enabling unifiedaccess to multiple data types according to one embodiment of theinvention.

FIG. 16 is a schematic block diagram of a system for enabling unifiedaccess to multiple data types according to one embodiment of theinvention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The invention relates to a system and method for caching a networkconnection. The invention sustains a connection between a server and aback-end database after a connection between the server and an end-userdevice has been disconnected.

FIG. 1 is a schematic block diagram of an overall system for storinghierarchical objects according to one embodiment of the invention. Thesystem includes a host computer 100 that includes transmission controlprotocol/Internet protocol (TCP/IP) proxy 102, one or more servers 104a-104 n, database 106, purger 108, global lock manager 110, andreplicator 112. The system may also include a remote application 114that is in communication with host computer 100.

TCP/IP proxy 102 enables host computer 100 to accept a TCP/IPconnection. After a TCP/IP connection is made with TCP/IP proxy 102, theconnection may be communicated to a server process. This enables TCP/IPproxy 102 to shield each server process from a potential failure in anyother server process. Servers 104 a-104 n may be used to maintain one ormore TCP/IP connections. Servers 104 a-104 n may be in communicationwith database 106 and may operate independent of each other to reduce achance of failure. Additionally, using this configuration, datacorruption is reduced.

Data corruption reduction is possible because each location on a servermay have a corresponding code location for code that may modify onlythat particular location. Therefore, the code may not be used to modifyother locations that may be referenced by other processes of the serverthat require updates. Additionally, a server may have multiple locationshaving the same name. Therefore, by limiting a location that the codemay modify, this reduces modification errors by modifying a location notintending to be modified. For example, if a server includes two (2)locations “1000” and a single code for modifying both locations, thecode may modify an incorrect location. This increases a likelihood ofincorrect data being processed. By using only a single code for eachlocation, this reduces a chance for data being corrupted.

Purger 108 may receive requests from one or more of servers 104 a-104 nto schedule automatic deletion of objects within database 106. Forexample, an application may schedule deletion of one or more HDLs two(2) weeks after creation. Purger 108 may be used to delete HDLs thathave been designated to be deleted after a predetermined time period.

Purger 108 may also be used to delete one or more HDLs after a last useexpiration. For example, an HDL may be scheduled for deletion after twoweeks. If a user modifies the HDL a day before the expiration of the twoweeks, the HDL may still be deleted after the two weeks has expired.Therefore, an HDL that may be desired to be retained may be deleted.Thus, purger 108 may be set to delete an HDL two weeks after a last useof the HDL. In this manner, HDLs may not be deleted if the HDL is stillin use. For example, purger 108 may be set to delete an HDL two weeksafter a last use as opposed to two weeks after creation.

Global lock manager 110 may be used to coordinate explicit recordlocking requests from remote application 114. A record lock request maybe a request from a user to prohibit one or more other users fromaccessing a particular object. A lock may be shared or exclusive, have await time that controls how long an application may wait beforeobtaining a lock, or have an expiration time that controls when a lockmay be automatically released. Global lock manager 110 may alsodynamically display currently held and pending locks.

Replicator 112 may be used to communicate, for example, using MQ Series,with other replicators. For example, replicator 112 may replicate HDLsduring an insert command. The insert operation may provide a name of alist of instances that may receive a copy of the HDL. A list-of-listsmay also be allowed and may be reduced and edited to reduce multipleinsertions at a single instance. The list-of-lists may be recursive.

FIG. 2 is a schematic block diagram of an HDL 200 stored according toone embodiment of the invention. HDL 200 may include HDCs embodied aslinked attribute value lists (LAVL) 202 a-202 n and linked attributevalue pairs (LAVP) 204 a-204 n. LAVLs 202 a-202 n may be a list of zero(0) or more LAVPs 204 a-204 n. LAVLs 202 a-202 n may function as aparent for LAVPs 204 a-204 n. An LAVL may contain another LAVL.Therefore, a hierarchical structure may be built to any level ofcomplexity. For example, an inheritance model may be created for aparticular data structure.

Each LAVP 204 a-204 n may include a header 302 and value 304 as shown inFIG. 3A. Value 304 may contain zero (0) or more bytes of data. Thelength of the value may be stored in header 302. Each header may have asyntax describing a format of the value. For example, a value may be anInteger, Unicode string, Timevalue, or application defined. An LAVP maybe six (6) words plus the content of the header length field.Preferably, header 302 includes at least six (6) words. Header 302 maybe used to identify an attribute of an HDL and its relationship to otherattributes.

Header 302 may include a previous LAVP 306, next LAVP 308, parent LAVL310, OID 312, length 314, pool ID 316, syntax 318, and data 320 as shownin FIG. 3B. Previous LAVP 306, next LAVP 308, and parent LAVL 310 may beused as pointers to other LAVPs and LAVLs. Previous LAVP 306, next LAVP308, and parent LAVL 310 may be implemented as relative offsets ratherthan actual pointers. For example, previous LAVP 306 may refer to theprevious LAVP by a distance in bytes rather than location of theprevious LAVP. Implementing previous LAVP 306, next LAVP 308, and parentLAVL 310 as relative offsets facilitates placing objects in sharedmemory segments and memory mapped disk files and transmission. By usingrelative offsets, an object may be referenced by different addresses anddifferent processes in the same or other systems. Therefore, LAVLs andLAVPs may not be required to be moved to different storage locations andmay reside in any place in memory. If an LAVP is not a member of anLAVL, previous LAVP 306, next LAVP 308, and parent LAVL 310 may bedesignated as null, for example, −1.

For an integer value defined using the following code:

#define my_oid 0x00040005

ost_create_int (my_oid, 27);

previous LAVP 306, next LAVP 308, and parent LAVL 310 may have a −1value indicating a null value, OID 312 may have a 0x00040005 value,length 314 may have a 4 value, pool 316 may have a zero (0) value,syntax 318 may have an ost_syntax_sint32 value, and an additionalelement 320 storing the integer value, that is, 27, may also beincluded.

Code for carrying out the invention may include various classes ofcalls. For example, the classes may include creation, identification,navigation, searching, comparison, manipulation, displaying/debugging,and destruction. The creation class may include a create call, theidentification may include an OID, syntax, length call, navigation mayinclude a previous, next, parent, first, last, scan, and traverse calls,searching may include a locate call, manipulation may include a join,weave, merge, unchain, and add calls, and the destruction class mayinclude a free call.

The following are examples of code that may be used for carrying out theinvention. Although the examples are written in C language, othercomputer languages may also be used. Preferably the following commandsare performed at the hardware level of a system using the invention.

To create an LAVL, the following syntax may be used:

#include <ost_lavls.h>

Lavl*ost_create_lavl (Oid)

Oid oid;

This function may be used to create an LAVL as shown in FIG. 3B. Thereturned LAVL pointer contains the address of a LAVL with the given OID.The LAVL may not be chained to any other LAVPs and contain no children.In other words the Previous, Next, LAVL, Parent, Head, and Tail pointersare NULL. OID may be an object identifier, for example, a name of anLAVL to be created.

To create a real value LAVP, the following syntax may be used:

#include <ost_lavls.h>

Lavp*ost_create_real (oid, value, tolerance, Unitid)

Oid oid;

double value;

Uint16 tolerance

Uint16 UnitID

This function creates a real value LAVP. The value may be described witha tolerance and a UnitID. The value may be the most likely value of thedata. The tolerance represents a percentage error that may be expectednot to exceed 95% of the time. The tolerance may be a 16 bit unsignednumber that represents 1/1000ths of a percent. This implies that thesmallest tolerance is 0% and the largest tolerance is +/−65.535%.

Pre-defined values for common tolerances may be:

#define MATCH_EXACTLY   0 /* 0% */ #define MATCH_NEARLY  1000 /* 1% */#define MATCH_CLOSETO  2000 /* 2% */ #define MATCH_APPROXIMATELY  5000/* 5% */ #define MATCH_AROUND 10000 /* 10% */ #define MATCH_ROUGHLY25000 /* 25% */

The UnitID may be a number from 1 to 499 that represents the dimensionof the value. UnitIDs may be found in ‘NAME’ records of the OSTconfiguration and the ost_clientlib.h C language file.

Example: To create a real value of 160+/−1% pounds:

ost_create_real (WEIGHT_OID, 160.0, MATCH_NEARLY, OST_UNIT_pounds);

Character strings may be represented by a variety of syntaxes thatindicate a character set and an LAVP value area that may include a one(1) word length followed by characters. A request for an LAVP's valuelength may be the length of a value area, not the length of the stringcontained therein. There may be two (2) basic types of calls to createcharacter strings. The first:

LAVP*0ST_Create_XXXXXX (Oid oid, char*text); may be used to create astring LAVP from a null terminated string.

The second:

LAVP*0ST_create_XXXXXX (Oid, oid, char*text, Sint 32 length), may beused to create a string from a non-null terminated string.

To create an integer LAVP, the following code may be used:

#define my_oid 0x00040005

ost_create_int (my oid, 27);

To create a unicode string LAVP from an ASCII string, the followingsyntax may be used:

#include <ost_lavls.h>

Lavp*ost_create_unicode_from_ascii (my_oid, “This is text”)

Lavp*ost_create_unicode_from_ascii (my_oid, “This is text”, 12)

Oid oid;

char*test;

Sint32 Length;

In this example, a header 302 of an LAVP may include the following:

previous LAVP 306, next LAVP 308, and parent LAVP 310 may have −1values, OID 312 may have a 0x00040005 value, length 314 may have a valueof 28 or more, pool 316 may have a zero (0) value, and syntax 318 mayhave an ost_syntax_unicode value. A value 304 of the LAVP may have a 12value and text including ₀T₀H₀I₀S₀ 8 ₀I₀S₀ 8 ₀T₀E₀X₀T.

To create an LAVP that contains a numeric value, the following syntaxmay be used:

#include <ost_lavls.h>

Lavp*ost_create_time_gmt(oid,time)

Oid oid;

Timeval time;

This function may be called to create an LAVP with syntaxOST_SYNTAX_TIME,GMT. The time argument may be interpreted in two ways:

An absolute time, then the time value represents the number ofmicroseconds since Jan. 0, 1970. The time may be represented as arelative time. For example, 5:30. That is, 5 and one-half hours from agiven time. Time values may be added or subtracted to obtain otherabsolute or relative time values. An absolute value may be added to arelative time value to obtain an absolute time value. For example, anabsolute time value of Jan. 1, 1970, plus a relative time value of five(5) and one-half hours yields an absolute time value of Jan. 1, 1970,5:30 a.m. Absolute time values may be subtracted from another absolutetime value to produce a relative time value. The relative time value maybe an amount of time between the two absolute time values. Additionally,relative time values may be added to each other to produce anotherrelative time value.

To create an LAVP that contains a numeric value, the following syntaxmay be used:

#include <ost_lavls.h>

Lavp*ost_create_time_gmt (oid, time)

Oid oid;

Timeval time;

To create a character string LAVP, the following syntax may be used:

#include <ost_lavls.h>

Lavp*ost_create_ascii (oid, text);

Lavp*ost_create_ascii (oid, text, textlen);

Lavp*ost_create_cp850 (oid, test);

Lavp*ost_create_cp850 (oid, text, textlen);

Lavp*ost_create_ebcdic (oid, text);

Lavp*ost_create_ebcdic (oid, text, textlen);

Lavp*ost_create_hexdata (oid, text);

Lavp*ost_create_hexdata (oid, text textlen);

Lavp*ost_create_ia5 (oid, text);

Lavp*ost_create_ia5 (oid, text, textlen);

Lavp*ost_create_iso6937 (oid, text);

Lavp*ost_create_iso6937 (oid, text, textlen);

Lavp*ost_create_iso88591(oid, text);

Lavp*ost_create_iso88591 (oid, text, textlen);

Lavp*ost_create_iso88592 (oid, text);

Lavp*ost_create_iso88592 (oid, text, textien);

Lavp*ost_create_iso88593 (oid, text);

Lavp*ost_create_iso88593 (oid, text, textlen);

Lavp*ost_create_iso88594 (oid, text);

Lavp*ost_create_iso88594 (oid, text, textlen);

Lavp*ost_create_iso88595 (oid, text);

Lavp*ost_create_iso88595 (oid, text, textlen);

Lavp*ost_create_iso88596 (oid, text);

Lavp*ost_create_iso88596 (oid, text, textlen);

Lavp*ost_create_iso88597 (oid, text);

Lavp*ost_create_iso88597 (oid, text, textlen);

Lavp*ost_create_iso88598 (oid, text);

Lavp*ost_create_iso88598 (oid, text, textlen);

Lavp*ost_create_iso88599 (oid, text);

Lavp*ost_create_iso88599 (oid, text, textlen);

Lavp*ost_create_isot61 (oid, text);

Lavp*ost_create_isot61 (oid, text, textlen);

Lavp*ost_create_numeric (oid, text);

Lavp*ost_create_numeric (oid, text, textlen);

Lavp*ost_create_printabl (oid, text);

Lavp*ost_create_printabl (oid, text, textlen);

Oid oid;

char*text;

Sint32 textlen;

An example of creating an ASCII string, for example, “This is text,” mayinclude the following syntax:

ost_create_ascii (my_oid, “This is text”)

A header 302 of an LAVP storing this information may include a previousLAVP 306, next LAVP 308, and parent LAVP 310 having −1 values, an OID312 having a 0x00040005 value, a length 314 value of 16 or more, a poolID of 0, and a syntax of ost_syntax_ascii. The value 304 of the LAVP mayinclude a 12 value and text including “This is text”.

To create a unicode string LAVP from a ASCII string, the followingsyntax may be used:

#include <ost_lavls.h>

Lavp*ost_create_unicode_from_ascii(oid,text)

Lavp*ost_create_unicode_from_ascii(oid,text,length)

Oid oid;

char*text;

Sint32 Length;

To get a syntax of an LAVP, the following syntax may be used:

#include <ost_lavls.h>

Syntax ost_syntax(lavp)

Syntax ost_syntax(lavl)

Lavp*lavp;

Lavl*lavl;

The ost_syntax function obtains the syntax of the LAVP. If the argumentis a NULL value, for example, −1, a SIGBUS error may result.

To get the address of the previous LAVP in an LAVL, the following syntaxmay be used:

#include <ost_lavls.h>

Lavp*ost_prev(lavp)

Lavp*ost_prev(lavl)

Lavp*lavp;

Lavl*lavl;

The ost_prev function obtains the address of the previous LAVP in aLAVL. If the argument is NULL, is the first LAVP in a LAVL, or the LAVPis not in a LAVL then NULL may be returned.

To get the address of the next LAVP in an LAVL, the following syntax maybe used:

#include <ost_lavls.h>

Lavp*ost_next(lavp)

Lavp*ost_next(lavl)

Lavp*lavp;

Lavl*lavl;

The ost_next function obtains the address of the next LAVP in a LAVL. Ifthe argument is NULL, is the last LAVP in a LAVL, or the LAVP is not ina LAVL then NULL is returned.

To get the address of a parent LAVL from an LAVP, the following syntaxmay be used:

#include <ost_lavls.h>

Lavl*ost_lavl(lavp)

Lavl*ost_lavl(lavl)

Lavp*lavp;

Lavl*lavl;

The ost_lavl function obtains the address of the parent LAVL for anLAVP. If the argument is NULL or the LAVP is not in a LAVL then NULL isreturned.

To search the database for a Real value the following code may be used:

where_clause=ost_EQ( ost_create_real (WEIGHT_OID, MATCH_AROUND, 72.0,OST_UNIT_kilograms));

To add an LAVP to an LAVL, the following syntax may be used:

#include <ost_lavls.h>

Lavl*ost_add(existing_lavl,new_lavp)

Lavl*ost_add(existing_lavlnew_lavl)

Lavl*existing_lavl;

Lavp*new_lavp;

Lavl*new_lavl;

This function may be called to add an LAVP or LAVL to a LAVL. TheLAVP/LAVL may be from any LAVL that it may be a member of and isrechained to the end (bottom) of the LAVL. If the LAVP is not a memberof a LAVL then a simple add may occur. If either operand is NULL then noaction may occur.

This function is very commonly used in conjunction with the ost_create_() function as follows:

Before L1 L3 P1 P11 P2 P12 P3 P13 L2 L4 P4 P14 P5 P15 P6 P16 P7 P17 P8P18 P9 P19 ost_add(L1,P15); After L1 L3 P1 P11 P2 P12 P3 P13 L2 L4 P4P14 P5 P6 P16 P7 P17 P8 P18 P9 P19 P15

To disassociate an LAVP or LAVL from a LAVL, the following syntax may beused:

#include <ost_lavls.h>

void ost_unchain(lavp)

void ost_unchain(lavl)

Lavp*lavp;

Lavl*lavl;

This function may be used to dissociate an LAVP or LAVL from a LAVL. TheLAVL's address may be determined from the LAVP by internally callingost_lavl(lavp). The LAVL's head and tail may be updated if required andthe LAVP's previous and next siblings are rechained together asappropriate. The argument LAVP's LAVL, previous, and next pointers areset to NULL to indicate that the LAVP is no longer a member of any LAVL.The LAVP may be indicated as a loose object if this feature is enabled.The contents of the LAVP may then be preserved.

To display an LAVP or LAVL, the following syntax may be used:

#include <ost_lavls.h>

extern FILE*ost_display_FILE;

void ost_display (lavl)

void ost_display (lavp)

Lavl*lavl;

Lavp *lavp;

OID 312 may be used to identify a name of an object. Length 314 may beused to identify a length of the object. Pool ID 316 may be used toidentify a group to which that object may be associated. Syntax 318 maybe used to identify a format of the LAVL's value. Data 320 may be usedto store the LAVL's data. Length 314 may be computed based on value 304and syntax 318. Pool ID 316 preferably uses an eight (8) bitidentification.

FIG. 4 illustrates an LAVP storing a string according to one embodimentof the invention. As shown in FIG. 4, a string object 400 may includestring length 402, string 404, and optional spare space 406. Stringlength 402 may be used to identify the length of string 404. Optionalspare space 406 may be used to expand string 404 if desired.

The invention may also enable storing concepts and colors. FIG. 5illustrates an HDL 500 storing a concept. The concept stored as shown isa man's clothing ensemble. HDL 500 may include all information relatingto one ensemble. By storing all the information together as a singleobject only, a single call from a server to request all or a portion ofHDL 500 may be needed. HDL 500 includes the following HDCs: ensemble502, color 504, shirt 506, pants 508, and shoes 510. HDL 500 alsoincludes the following HDEs: size 512, material 514, sleeve 516,material 518, inseam 520, material 522, size 524, and color-black 526.HDEs 512-516 identify particular criteria for HDC 506. That is, HDEs512-516 indicate the size, material, and sleeve for shirt 506 in theensemble. HDEs 518-520 indicate a material and inseam for pants 508 inthe ensemble. HDEs 522-526 indicate the material, size, and color forshoes 510 in the ensemble. It should be noted that color HDC 504indicates a color for each portion of the ensemble following that HDC.HDE 526, however, indicates a particular color for the shoes. Therefore,the color indicated in HDC 504 may be overridden by the color indicatedin HDE 526. Each HDC and HDE 504-526 may include descriptions for eachportion of the ensemble. Therefore, if a user submits a call, forexample, for ensembles having black shoes, HDL 500 may be retrieved. Ifthe user then further desires to view information regarding otherportions of ensemble 502, HDL 500 includes all of the information andtherefore, the system does not require another call to a server torequest any additional information because the information may alreadybe included in HDL 500.

A user may navigate through HDL 500 by drilling-up or drilling-down. Forexample, for HDE 522, a user may be presented with information regardingHDE 520 or other portion of the ensemble. Although not shown in FIG. 5,the ensemble may also include other information such as, for example,accessories or other clothing.

Additionally, because entire HDL 500 is retrieved, no parsing of thedata contained therein may be necessary. The system may not be requiredto parse through one or more HDLs and determine particular data elementsthat satisfy a request and retrieve only those data elements. Thisreduces processing time because parsing of data may not be necessary anddrilling-down or up may be performed at a client and not at a server.

Storing conceptual information as a single hierarchical object maydecrease retrieval time. As stated above, because all informationregarding a particular concept is stored within a single object, theobject may be stored locally by an application and is not required tocontact a server for retrieving additional information regarding theconcept.

As data is stored, an application designer or other user may store datarelated to a particular concept as a hierarchical tree. The applicationdesigner or other user has the flexibility to include as muchinformation as desired into a single object. This flexibility enablesapplication designers or other users to store complete concepts within asingle object.

Additionally, HDLs may include references to other HDLs. For example, anHDL that describes a man's clothing ensemble as shown in FIG. 5 mayinclude a reference to an HDL that contains all information regardinganother ensemble for a man. This may be performed by inserting a whereclause in a code describing the ensemble stored in the HDL that callsanother ensemble HDL, retrieves the other ensemble HDL, and inserts thatother ensemble HDL into the first ensemble HDL. In this manner, HDLs mayinclude other HDLs as well.

The invention also enables storing colors. Colors may be stored asequations identifying three (3) dimensional color space. Therefore, acolor attribute may be ascribed to a particular data element. A colorattribute may be stored by identifying a red, green, and bluecharacteristic of a particular color using a predetermined range ofvalues. For example, each red, green, and blue characteristic of a colormay be expressed as a percentage from zero (0) to one-hundred (100).Alternatively, if a color is stored as a one byte of data, eachattribute may be assigned a value from zero (0) to two-hundredfifty-five (255). Therefore, red, green, and blue attributes may bedescribed as any relative range of values.

For example, a color having red, green, and blue attributes equal tozero (0) may define a black color. Alternatively, if each red, green,and blue attribute is defined as one-hundred (100) percent of eachcolor, then the color defined may be white. Furthermore, if a colorattribute is expressed as fifty (50) percent red, fifty (50) percentgreen, and fifty (50) percent blue, the color may be gray.

A color attribute may be defined as a distance from each red, green, andblue attribute as shown on a three (3) dimensional color space.Therefore, each color may be defined as:D=√{square root over ((R ₁ −R ₂)²+(B ₁ −B ₂)²+(G ₁ −G ₂)²)}{square rootover ((R ₁ −R ₂)²+(B ₁ −B ₂)²+(G ₁ −G ₂)²)}{square root over ((R ₁ −R₂)²+(B ₁ −B ₂)²+(G ₁ −G ₂)²)}where D equals a distance between two (2) colors having R1, B1, G1 andR2, B2, and G2 attributes, respectively. The distance may be defined asthe square root of the sum of the squares of the differences of eachcolor component. By having each color component stored as one (1) byteof data, therefore, there may be a total of twenty-four (24) bits thatmay be used to express a plurality of colors. Thus, at least 16 milliondifferent colors may be represented.

The invention also enables statistical matching. Statistical matchingmay be used to retrieve real values within a predetermined tolerance.For example, an object may be stored that describes properties of abrick. The brick may have a length, width, height, weight, etc. A usermay request objects describing a brick that has a weight of five (5)pounds plus or minus five (5) percent. The user may request suchinformation using any known input device, for example, a keyboard,mouse, voice recognition software, touchscreen, etc. The request may besubmitted to a server. The server may assume a normal distribution. Theserver may convert the units of measurement, that is, pounds, into otherequivalent units of measurement, for example, kilograms, tons, grams,etc. A normally distributed statistical curve may then be calculated forthe tolerance specified.

The statistical curve may be used to determine whether any objects matchthe user's request. This may be done by calculating a statistical curvefor all objects related to the user's request. The statistical curve forthe requested objects may then be superimposed on the statistical curvefor all of the objects. A match may be determined by an area under bothcurves within the predefined tolerance. If there are no portions of thecurves that overlap within the predefined tolerance, a no match resultmay be presented to the user. If, however, the curves overlap within thepredefined tolerance, a match result may be presented to the user.

Therefore, a statistical curve for a brick weighing five (5) pounds plusor minus five (5) percent would indicate that bricks having a weight ina range of 4.75 pounds to 5.25 pounds are acceptable. The server maythen determine objects comprising information relating to bricks havinga weight within that range. The server may then return to a user a listof objects that match the requested specification. The objects meetingthe specification may also be presented to the user. A match/no matchindicator may also be presented to the user. Furthermore, an indicationof a number of matching objects out of a total number of objects mayalso be presented to the user.

As indicated above, the syntax used to search for objects having aparticular specification includes a value, tolerance, and unit. Theinvention may index compatible units. For example, an index for weightmay include pounds, kilograms, grams, tons, etc.

The invention also enables fizzy searching capability. An index of realvalues containing units may be searched. A search argument used forsearching the index may include a value, tolerance, and unit. Theinvention may first convert an index entry and search argument to astandard unit. A decision may then be made depending on a statedtolerance of the index entry and the search argument. The index entrymay be assumed to be normally distributed and the tolerance expressed asa percentage may be taken to be the second standard deviation interval(95%). The tolerance may then be used to calculate the statisticalprobability that an index entry is less than, equal to, or greater thana search argument. A search argument may also contain concepts such asexactly, close to, nearly, approximately, about, and roughly. Theseconcepts may be used in both the storage and retrieval of data and maybe pre-set by a system administrator. For example, a systemadministrator may pre-set a nearby tolerance to one (1) percent, anexactly tolerance to zero (0) percent, an about tolerance to ten (10)percent, etc.

Search arguments may also be used to perform searches on simple indexes,for example, searching a database for names of one or more persons. Thesyntax for a search command may include the following:

#include <ost_clientlib.h>

Lavl*ost_queue_search (session, where_clause)

OST_Session*session;

Lavl*where_clause

The search algorithm may be implemented using Venn Sets. When an objectis inserted into the database with the index option enabled, then eacheligible OID is indexed. An index may contain a list of each uniquevalue for the OID. For each unique value a list of Object Numbers may bemaintained. For example, the following objects may be stored in thedatabase and indexed on GIVENNAME_OID and SURNAME_OID.

Object 1 L (FAMlLY_OID) ASCII (SURNAME_OID) = ‘SMITH’ L (FATHER_OID)ASCII (GIVENNAME_OID) = ‘JOHN’ L (MOTHER_OID) ASCII (GIVENNAME_OID) =‘JANE’ L (SON_OID) ASCII (GIVENNAME_OID) = ‘JOE’ L (SON_OID) ASCII(GIVENNAME_OID) = ‘JOSHUA’ L (DAUGHTER_OID) ASCII (GIVENNAME_OID) =‘JANET’ ASCII (SURNAME_OID) = ‘JONES’ L (DAUGHTER_OID) ASCII(GIVENNAME_OID) = ‘JULIA’ Object 2 L (FAMILY_OID) ASCII (SURNAME_OID) =‘JONES’ L (FATHER_OID) ASCII (GIVENNAME_OID) = ‘SAM’ L (MOTHER_OID)ASCII (GIVENNAME_OID) = ‘SHIRLEY’ L (SON_OID) ASCII (GIVENNAME_OID) =‘JOE’ L (SON_OID) ASCII (GIVENNAME_OID) = ‘SHAWN’ Object 3 L(FAMILEY_OID) ASCII (SURNAME_OID) = ‘ADDAMS’ L (FATHER_OID) ASCII(GIVENNAME_OID) = ‘GOMEZ’ L (MOTHER_OID) ASCII (SURNAME_OID) = ‘JONES’ASCII (GIVENNAME_OID) = ‘MORTICIA’ L (SON_OID) ASCII (GIVENNAME_OID) =‘PUGSLY’ L (DAUGHTER_OID) ASCII (GIVENNAME_OID) = ‘WEDNESDAY’

A search command may also contain Boolean logic such as “and” and “or.”An example of syntax that may be used to create an “and” condition foruse in a search argument may be the following:

#include <ost_clientlib.h>

Lavl*ost_AND(lavl1, lavl2)

Lavl*lavl1;

Lavl*lavl2;

The ost_AND function may create an AND condition in a Search Argument.For example, to express the condition WHERE(GIVENNAME_OID=‘Jane’) AND(SURNAME_OID=‘Smith), the following code may be used:

Lavl*where;

Lavl*arg1;

Lavl*arg2;

arg1=ost_EQ(ost_create_ascii(GIVENNAME_OID, “Jane”));

arg2=ost_EQ(ost_create_ascii(SURNAME_OID, “Smith”));

where=ost_AND(arg1,arg2);

To create an “or” condition for use in a search argument, the followingsyntax may be used:

#include <ost_clientib.h>

Lavl*ost_OR(lavl1,lavl2)

Lavl*lavl1;

Lavl*lavl2;

The ost_OR function creates an OR condition in a Search Argument. Forexample, to express the condition WHERE (GIVENNAME_OID=‘Jane’) OR(SURNAME_OID=‘Smith’), the following code may be used:

Lavl*where;

Lavl*arg1;

Lavl*arg2;

arg1=ost_EQ(ost_create_ascii(GIVENNAME_OID, “Jane”));

arg2=ost_EQ(ost_create_ascii(SURNAME_OID, “Smith”));

where=ost_OR(arg1,arg2);

The invention preferably includes units of measurements related to aplurality of measurements and may convert among each unit within aparticular category of measurement. The invention preferably includes aunits table compiled once and may be edited by a user as needed.

The invention also enables multi-indexing of objects. The objects may beindexed according to ASCII code, string, or other criteria If an objectis not indexed, the object is preferably assigned a serial number. Anobject may include multiple indexes and cells within an index mayinclude multiple values. For example, letters A, B, C, and D may beindexed as R1, R2, R3, and R4, respectively. Letter E, however, may beindexed as R1. Therefore, one cell or record may have multiple aliases.The indexes are preferably created over an entire object, althoughindexes may be created based on particular fields. Indexes over anentire record, however, may yield broader results for searches performedon the index. For example, a search of an index for families having afemale child may yield objects that comprise a mother and a child wherethe child may not necessarily be female. This may be due to the mothersatisfying the female portion of the search request and the childsatisfying the child portion of the search request.

The invention also enables creating multi-indexes with one (1) insert.Multi-indexing may be enabled because when an object is created, eachHDC and HDE provided in the object may be indexed upon creation of theobject. Therefore, it may not be necessary to individually insert one ormore HDCs or HDEs from an object into an index. The invention mayautomatically index each HDC and HDE in an object

The invention also enables reference to back end databases such as LDAP,DB2, and Oracle. When referencing an LDAP database, the invention mayreturn LDAP entries as LAVLs rather than Bit Error Rate (BER) encodedstrings. This enables navigation among various data elements.Additionally, as described above, the invention may return entire HDLsthat include all information relating to a particular data element. Thisreduces the number of calls needed to be made against a record at aserver. Navigation may be performed backward and forward and to detectand process multi-valued LDAP entries.

Another advantage is that the invention automatically distinguishessyntaxes of objects retrieved from a back-end database. The inventionalso stores the syntax and value for a particular record. Therefore, theinvention provides unified access to multiple types of databases byproviding a common application programming interface.

The invention also enables maintaining of network connections. After aconnection to a back-end database, for example, from a server or otherdevice is established, the connection to the back-end database may bemaintained. Therefore, if a user cancels a connection to a server, aconnection between the server and the back-end database may bemaintained. Thus, if a user reconnects to the server and requestsadditional information from the back-end database, the server does notneed to reconnect to the back-end database because the previousconnection has been maintained. Therefore, processing time is reducedbecause reconnection time may not be necessary. The server may determinewhether an open connection exists for one or more particular devices,for example, by maintaining a list of open connections. Therefore, ifthe server receives a request for information from a database or otherdevice, the server may check the list of open connections and determinewhether a connection to that database or device exists. If adetermination is made that a connection is open, the server may use thatconnection to satisfy the request. This reduces a need for a server toreestablish a connection to a particular device on numerous occasions.

The invention also enables searching using extended regular expressionsand Unicode strings in the spirit of UNIX eGREP(1) command. For example,a search may be performed on ASCII strings that include a three (3)digit code. ASCII strings may include key 001, key 002, and key 003. Asearch may be performed on the ASCII strings using an extended regularexpression that may be arbitrarily complex. For example, a searchexpression may be “key00[12]”. A search of the ASCII strings using thisexpression may yield key001 and key002.

Additionally, Unicode strings may also be searched. Unicode stringsearches may be SQL-like statements. For example, a Unicode stringsearch may be “text”. This enables searches of exact Unicode strings.

The invention may also include a memory debugging feature. The featuremay be implemented using, for example, seven levels of diagnostic data,one level may be an environmental “M” option. Setting this option maycause all LAVPs to be set to a particular format when the LAVP is freedfrom memory. This may be used to increase the likelihood that an LAVP isnot referenced after it is free. The debugging option may also includean environmental “L” option that causes loose object detection. Thisoption may cause an LAVLs application programming interface to maintaina list of every LAVP that is not in an LAVL. The debugging feature mayalso include an option that disables an internal object identifier lookaside buffer. The look aside buffer may be used to increase theperformance of an LAVP locator function. If a loose object detectionoption is enabled, the system may display contents of a loose objectlist that may be invoked at any time. This may provide several levels ofdiagnostic data that may facilitate locating objects and their creation.Objects may automatically be placed onto and removed from a loose objectlist whenever a parent pointer is made non-null or null, respectively.

FIG. 6A illustrates a system 600 for managing one or more HDLs. System600 may include an HDC creating module 602, HDL creating module 604,command creating module 606, command submitting module 608, and HDEcreating module 610. HDC creating module 602 may be used to create anHDC to be stored within an HDL. If an HDL is created, HDL creatingmodule 604 may be used to create the HDL. The HDCs and HDLs created, maybe created using one or more commands input by a user. Command creatingmodule 606 may be used to enable the user to create the commands forcreating one or more HDCs and HDLs.

Command submitting module 608 may be used to submit the commands to aserver for processing. Additionally, an HDE creating module 610 may beused to create one or more HDEs that may be included in one or more HDCsand HDLs.

After each HDC, HDE, and HDL is created, storing module 612 may be usedto store the HDCs, HDEs, and HDLs at a location in memory of a client orother device. An identifier assigning module 614 may be used to assignan identifier to one or more HDLs.

As described above, an HDL may include a length field. Therefore, lengthdetermining module 616 may be used to determine a length of data storedby an HDL. A format determining module 618 may also be used to determinea format of the data stored by the HDL.

After one or more commands are submitted to a server by commandsubmitting module 608, a response from the server may be received usingresponse receiving module 620. A response analyzing module 622 may beused to analyze the response received from the server. The analysis mayinclude determining whether the response includes one or more HDLs,whether the HDLs include one or more HDCs or HDEs, determining datastored by the HDLs, or other analysis.

If a determination is made that the response includes one or more HDLs,an HDL analyzing module 624 may be used to analyze the HDLs. Theanalysis may included determining whether the HDL includes one or moreHDCs or HDEs, data stored by the HDL, or other analysis. Navigatingmodule 626 may be used to navigate either forward or backward through anHDL. Manipulating module 628 may be used to manipulate one or more HDLs.Manipulating the HDLs may include joining two or more HDLs, weaving twoor more HDLs, merging or adding two or more HDLs together, unchaining anHDC or HDE from and HDL, etc. A freeing module 630 may also be used tofree an HDC, HDE, or HDL. Preferably, freeing an HDC, HDE, or HDLincludes removing the HDC, HDE, or HDL from an HDL. This may beequivalent to a delete operation.

FIG. 6B illustrates a method for managing HDLs according to oneembodiment of the invention. The method may include a create HDC step650. Step 650 may be used to create one or more HDCs. A create HDL step652 may then be used to create one or more HDLs. The HDLs may includeone or more of the HDCs created using step 650. A create command step654 may be used to create a command that stores data in the HDCs. Instep 656, the command created using step 654 may be submitted to, forexample, a server.

A create HDE step 658 can then be used to create one or more HDEs. TheHDEs may be included in an HDC and/or HDL. In step 660, the HDL may bestored to, for example, an object store. In assign identifier step 662may be used to assign an identifier to the HDL stored. Steps 664 and 666may be used to determine a length and format of data in the HDL stored.

FIG. 7 illustrates a server 700 that may be used for managing HDLs.Server 700 may include a communications module 702, command receivingmodule 704, execution module 706, response creating module 708, responsetransmitting module 710, replicating module 712, purging module 714,global locking module 716, index creating module 718, and referencingmodule 720. Communications module 702 may be used to communicate withone or more clients. The communications are preferably transmitted overa network, for example, the Internet. The communications may use anyknown communication method.

Command receiving module 704 may be used to receive one or more commandsfrom a client. Execution module 706 may execute the commands received bycommand receiving module 704. Response creating module 708 may thencreate a response to the commands received and executed by executionmodule 706. Response transmitting module may transmit the response tothe client.

Replicating module 712 may be used to replicate one or more HDLs, HDCs,or HDEs. Replication may be performed in response to a command receivedfrom a client by command receiving module 704. Purging module 714 mayalso be used to purge one or more HDLs, HDCs, or HDEs. Purging mayinclude deleting an HDL, HDC, or HDE from a memory of server 700. Globallocking module 716 may be used to prevent access to one or more HDLs bya particular user. For example, global locking module 716 may prohibitone or more users from accessing the HDL. Global locking module 716 mayprohibit access based on attributes stored within a user profile orprovided in an HDL.

Index creating module 718 may be used to create an index based on one ormore HDLs. Any HDCs or HDEs included in an HDL may be used for creatingan index of HDCs or HDEs included in each HDL. Index creating module 718may create multiple indexes upon creation of an HDL. Therefore, if oneHDL is created, multiple inserts may be created in an index by indexcreating module 718. Referencing module 720 may be used to reference,for example, one or more back-end databases. The back-end databases mayinclude an LDAP, Oracle, or DB2 database. Referencing module 720 mayenable an entire database to be referenced by an HDL. For example, anHDL may include an HDC that references an Oracle database. Therefore,when the HDL that references the Oracle database is requested, theOracle database is retrieved along with the HDL requested. This reducesthe number of calls that may be necessary for retrieving the Oracledatabase. Thus, the HDL requested and the Oracle database are retrievedusing a single call.

FIG. 8 illustrates a system 800 for statistical matching according toone embodiment of the invention. System 800 may include an HDL requestreceived in the module 802, searching module 804, requests satisfyingdetermining module 806, first statistical curve determining module 808,second statistical curve determining module 810, overlap determiningmodule 812, converting module 814, HDL presenting module 816, matchresult presenting module 818, non-match result presenting module 820,and indicating module 822. HDL request receiving module 802 may be usedto receive a request for one or more HDLs. Searching module 804 may thensearch, for example, an object store, for one or more HDLs satisfyingthe request. Request satisfying determining module 806 may be used todetermine whether one or more HDLs in the object store satisfy therequests. If a determination is made that one or more HDLs satisfy therequest, first statistical curve determining module 808 may be used todetermine a statistical curve for HDLs described by the request.

Second statistical curve determining module 810 may then be used todetermine a statistical curve for one or more HDLs stored by the objectstore that satisfy the request. Overlap determining module 812 may beused to determine whether any overlap exists between the firststatistical curve and the second statistical curve. The statisticalcurves may assume a normal distribution. Any overlap between the twocurves may be defined as a percentage match by a user. For example, auser may define overlap between the two statistical curves and a matchindicating a match of 95%.

Converting module 814 may be used to convert units presenting in arequest to a common set of units. For example, if a request indicatesthat HDLs describing bricks weighing in a certain range of grams,converting module 814 may convert the grams to, for example, pounds, tocoincide with units for weight stored by the object store. HDLpresenting module 816 may then be used to present one or more HDLs thatsatisfy the request. Alternatively, a match result or non-match resultmay be presented using modules 818 or 820, respectively. Indicatingmodule 822 may also be used to indicate a closeness of HDLs matching therequest. For example, indicating module may indicate that three-hundred(300) of five-hundred (500) HDLs satisfied the request.

FIG. 9 illustrates a system 900 for caching a network connection. System900 may include a first connection request receiving module 902, firstconnection establishing module 904, second connection requesting module906, second connection establishing module 908, second connectionmaintaining module 910, disconnection request receiving module 912,disconnecting module 914, and connection sustaining module 916. Firstconnection request receiving module 902 may be used to receive aconnection request from, for example, a client device, at a server.First connection establishing module 904 may be used to establish aconnection between the client device and the server. Second connectionrequesting module 906 may then be used to request a second connectionfrom the server to an end device, for example, a database. Secondconnection establishing module 908 may then be used to establish asecond connection between the server and the database. Second connectionmaintaining module 910 may be used to maintain a record of connectionsestablished between the server and an end device. For example, therecord may be a list of open connections between the server and otherend devices.

Disconnection request receiving module 912 may be used to receive adisconnection request from a client device. Disconnecting module 914 maybe used to disconnect the connection between the client device and theserver. Although the connection between the client device and the servermay be disconnected, connection sustaining module 916 may be used tosustain the connection between the server and the end device. Therefore,if a first connection request is received after a connection between aclient device and a server has been disconnected, and a client devicerequest information from an end device to which the server is alreadyconnected, the server may not be required to reestablish the connectionwith the end device. In this manner the server maintains openconnections with end devices for a predetermined period of time. Thisreduces connection time and does not require a server to reestablishconnections with end devices each time a request is received forinformation from a particular end device.

FIG. 10 is an illustration of a method for caching in a networkconnection. The method may include a receive first connection request1010. Step 1010 may receive a first connection request from a clientdevice at a server. In step 1012, a first connection may be establishedbetween the client device and the server. In step 1014, the server mayrequest a second connection between the server and an end device. Forexample, the server may have received a search request from the clientdevice to search, for example, a back end database. Therefore, theserver may need to request a connection to the back end database. Step1016 may be used to establish the second connection between the serverand the back end database. In step 1018, a second connection record maybe maintained for open connections between the server and the back enddatabase and any other end devices.

In step 1020, the server may receive a disconnection request from theclient device. Step 1022 may be used to disconnect the first connectionbetween the client device and the server. Step 1024 may be used,however, to sustain the second connection between the server and backend database and other end devices. In this manner, if a server receivesa request to perform an operation at a back end database or other enddevice to which the server has previously established a connection, theserver may not be required to reestablish the connection. A search ofthe second connection record may be performed to determine whether aconnection has previously been established and whether that connectionhas been sustained. If a search of the connection record determines thata connection to the particular end device requested, the server may usethat open connection instead of requesting another connection to the enddevice. This reduces connection time.

FIG. 11 illustrates a method for searching extended regular expressionsaccording to one embodiment of the invention. The method may include areceive search request step 1102. Step 1102 may be used to receive anextended regular expression search request from one or more users. Instep 1104, the extended regular expression provided in the searchrequest may be parsed to determine particular elements of the expressionfor which to search An object store may then be searched to locateextended regular expressions satisfying the search request in step 1106.If one or more extended regular expressions that satisfy the searchrequest are located, step 1108 may be used to present the extendedregular expressions to the user.

FIG. 12 is an illustration of a system 1200 for searching extendedregular expressions. System 1200 may include a receiving module 1202,parsing module 1204, searching module 1206, and presenting module 1208.Receiving module 1202 may be used to receive one or more search requestsfor extended regular expressions from one or more users. Parsing module1204 may be used to parse the extended regular expressions provided inthe search request to determine particular elements of the extendedregular expression for which to search. Presenting module 1208 may thenbe used to present any extended regular expression located as a resultof the search.

FIG. 13 is an illustration of a method for multi-indexing of objects. Acreate HDL step 1302 may be used to create one or more HDLs. Aftercreating the HDLs, step 1304 may be used to determine one or more fieldsincluded in the HDLs. Based on the fields determined in step 1304, step1306 may be used to create an index of data included in the fields. Step1306 may create multiple indexes based on a single HDL created. Forexample, data contained in the fields may be used to create multipleindexes based on a type of index created. For example, for HDLs thatinclude personal information of one or more users, indexing may becreated based on first name, last name, gender, or other criteria.Therefore, an index may be created for each criteria After creating anindex, step 1308 may be used to assign an alias to data contained withinthe fields. An alias may be, for example, an HDL containing that data.

FIG. 14 is an illustration of a system 1400 for multi-indexing ofobjects. System 1400 may include an HDL creating module 1402, fielddetermining module 1404, index creating module 1406, and alias assigningmodule 1408. HDL creating module 1402 may be used to create one or moreHDLs. After the HDLs are created, field determining module 1404 may beused to determine the fields contained within the HDLs. Index creatingmodule 1406 may then be used to create one or more indexes based on thefields determined by field determining module 1404. Data included withinthe fields may be indexed according to a variety of criteria. Aliasassigning module 1408 may be used to assign an alias for the dataindexed. The alias may refer to the HDL that includes that data.

FIG. 15 illustrates a method for enabling unified access to multipledata types. The method may include a receive data request step 1502. Instep 1502, a server or other device may receive one or more datarequests from one or more users. A determine syntax step 1504 may beused to determine a syntax of the data requested. Step 1506 may then beused to determine an end device from which the data requested may beretrieved. After determining the end device, step 1508 may be used toaccess that end device. The data may then be retrieved in step 1510.Step 1512 may also be used to retrieve an attribute of the data.Preferably, the attribute is retrieved based on an attribute numberassigned to the attribute.

Step 1514 may then be used to store a value of the data. The syntax ofthe data may also be stored in step 1516. Step 1518 may be used to storethe data which may include the value and the syntax. The data may bestored as a character string.

FIG. 16 illustrates a system 1600 for enabling unified access tomultiple data types. System 1600 may include a receiving module 1602,determining module 1604, accessing module 1606, retrieving module 1608,and storing module 1610. Receiving module 1602 may be used to receiveone or more data requests from one or more users. Determining module1604 may be used to determine an end device from which the datarequested may be retrieved. After determining the end device, accessingmodule 1606 may be used to access the end device. Retrieving module 1608may then be used to retrieve the data requested and possibly anattribute of the data. After retrieving the data and possible attribute,storing module 1610 may be used to store the data and attribute.

The foregoing description of a system and method for storinghierarchical objects is illustrative, and changes in the aboveconstruction and sequences of operation may occur to persons skilled inthe art. For example, although multiple modules are shown for carryingout the invention, additional or fewer modules may be used and multiplemodules may be positioned in various locations. The scope of theinvention is accordingly intended to be limited only by the followingclaims.

1. A method for caching a network connection, comprising the steps of:receiving a connection request for at least one first connection betweenat least one terminal and a server; establishing the at least one firstconnection between the at least one terminal and the server; requestingat least one second connection between the server and at least onedatabase, wherein the database includes at least one self definingentity, the self defining entity including at least one of ahierarchical data list, a hierarchical data element, and a hierarchicaldata container; establishing the at least one second connection;retrieving the at least one self defining entity from the at least onedatabase via the second connection; and maintaining a record of the atleast one second connection established.
 2. The method of claim 1,further comprising the step of receiving a disconnection request for theat least one first connection from the at least one terminal.
 3. Themethod of claim 2, further comprising the step of disconnecting the atleast one first connection.
 4. The method of claim 3, further comprisingthe step of sustaining the at least one second connection after the atleast one first connection has been disconnected.
 5. The method of claim1, wherein the record includes a list of established second connections.6. A system for caching a network connection, comprising: connectionrequest receiving means for receiving a connection request for at leastone first connection between at least one terminal and a server;connection establishing means for establishing the at least one firstconnection between the at least one terminal and the server; connectionrequesting means for requesting at least one second connection betweenthe server and at least one database, wherein the database includes atleast one self defining entity, the self defining entity including atleast one of a hierarchical data list, a hierarchical data element, anda hierarchical data container; connection establishing means forestablishing the at least one second connection; data retrieval meansfor retrieving the at least one self defining entity from the at leastone database via the second connection; and maintaining means formaintaining a record of the at least one second connection established.7. The system of claim 6, further comprising disconnection requestreceiving means for receiving a disconnection request for the at leastone first connection from the at least one terminal.
 8. The system ofclaim 7, further comprising disconnecting means for disconnecting the atleast one first connection.
 9. The system of claim 8, further comprisingconnection sustaining means for sustaining the at least one secondconnection after the at least one first connection has beendisconnected.
 10. The system of claim 6, wherein the record includes alist of established second connections.
 11. A system for caching anetwork connection, comprising: a connection request receiving modulethat receives a connection request for at least one first connectionbetween at least one terminal and a server; a connection establishingmodule that establishes the at least one first connection between the atleast one terminal and the server; a connection requesting module thatrequests at least one second connection between the server and at leastone database, wherein the database includes at least one self definingentity, the self defining entity including at least one of ahierarchical data list, a hierarchical data element, and a hierarchicaldata container; a connection establishing module that establishes the atleast one second connection; a data retrieval module that retrieves theat least one self defining entity from the at least one database via thesecond connection; and a connection maintaining module that maintains arecord of the at least one second connection established.
 12. The systemof claim 11, further comprising a disconnection request receiving modulethat receives a disconnection request for the at least one firstconnection from the at least one terminal.
 13. The system of claim 12,further comprising a disconnecting module that disconnects the at leastone first connection.
 14. The system of claim 13, further comprising aconnection sustaining module that sustains the at least one secondconnection after the at least one first connection has beendisconnected.
 15. The system of claim 11, wherein the record includes alist of established second connections.
 16. A processor readable mediumcomprising processor readable code for caching a network connection,comprising: connection request receiving code that causes a processor toreceive a connection request for at least one first connection betweenat least one terminal and a server; connection establishing code thatcauses a processor to establish the at least one first connectionbetween the at least one terminal and the server; connection requestingcode that causes a processor to request at least one second connectionbetween the server and at least one database, wherein the databaseincludes at least one self defining entity, the self defining entityincluding at least one of a hierarchical data list, a hierarchical dataelement, and a hierarchical data container; connection establishing codethat causes a processor to establish the at least one second connection;data retrieval code that causes a processor to retrieve the at least oneself defining entity from the at least one database via the secondconnection; and connection maintaining code that causes a processor tomaintain a record of the at least one second connection established. 17.The medium of claim 16, further comprising disconnection requestreceiving code that causes a processor to receive a disconnectionrequest for the at least one first connection from the at least oneterminal.
 18. The medium of claim 17, further comprising connectiondisconnecting code that causes a processor to disconnect the at leastone first connection.
 19. The medium of claim 18, further comprisingconnection sustaining code that causes a processor to sustain the atleast one second connection after the at least one first connection hasbeen disconnected.
 20. The medium of claim 16, wherein the recordincludes a list of established second connections.